Note 7 - Loans (Details) - Allowance for Loan Losses by Portfolio Segment and Based on Impairment Method (USD $) In Thousands, unless otherwise specified	Jun. 30, 2014	Dec. 31, 2013
Loans individually evaluated for impairment
Individually Evaluated - Allowance	$ 9,609	$ 13,284
Individually Evaluated - Balance	188,709	200,780
Loans collectively evaluated for impairment
Collectively Evaluated - Allowance	159,468	160,605
Collectively Evaluated - Balance	8,376,569	7,883,783
Total allowance	169,077	173,889
Total balance	8,565,278	8,084,563
Commercial Loans [Member]
Loans individually evaluated for impairment
Individually Evaluated - Allowance	2,717	2,519
Individually Evaluated - Balance	26,971	31,968
Loans collectively evaluated for impairment
Collectively Evaluated - Allowance	60,522	62,584
Collectively Evaluated - Balance	2,295,909	2,266,756
Total allowance	63,239	65,103
Total balance	2,322,880	2,298,724
Real Estate Construction Loans [Member]
Loans individually evaluated for impairment
Individually Evaluated - Allowance	143	3,460
Individually Evaluated - Balance	31,728	34,420
Loans collectively evaluated for impairment
Collectively Evaluated - Allowance	9,412	8,539
Collectively Evaluated - Balance	253,611	187,281
Total allowance	9,555	11,999
Total balance	285,339	221,701
Commercial Mortgage Loans [Member]
Loans individually evaluated for impairment
Individually Evaluated - Allowance	6,230	6,584
Individually Evaluated - Balance	113,251	114,544
Loans collectively evaluated for impairment
Collectively Evaluated - Allowance	77,165	78,169
Collectively Evaluated - Balance	4,194,919	3,908,507
Total allowance	83,395	84,753
Total balance	4,308,170	4,023,051
Residential Mortgage And Equity Lines Member
Loans individually evaluated for impairment
Individually Evaluated - Allowance	519	721
Individually Evaluated - Balance	16,759	19,848
Loans collectively evaluated for impairment
Collectively Evaluated - Allowance	12,351	11,284
Collectively Evaluated - Balance	1,622,667	1,506,684
Total allowance	12,870	12,005
Total balance	1,639,426	1,526,532
Installment And Other Loans [Member]
Loans collectively evaluated for impairment
Collectively Evaluated - Allowance	18	29
Collectively Evaluated - Balance	9,463	14,555
Total allowance	18	29
Total balance	$ 9,463	$ 14,555

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- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (g)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

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- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

+ References

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- Definition

The balance of financing receivables that were collectively evaluated for impairment.

+ References

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (h)

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The balance of financing receivables that were individually evaluated for impairment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 310

-SubTopic 10

-Section 50

-Paragraph 11B

-Subparagraph (h)

-URI http://asc.fasb.org/extlink&oid=35738203&loc=SL6953423-111524

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.7(d))

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-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 7

-Subparagraph d

-Article 9

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-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section L

-Subsection 1

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

+ References

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-Publisher FASB

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-SubTopic 10

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